Finding the balancing point of a sculpture

Hello all,

I am working with a sculptor and desiging a piece for a sculpture installation. I have created a script that dynamically divides up a rectangle into smaller rectangles and then runs a simple metal frame around plexiglass (in attached images). The issue now is, I have to find the 'balancing point' (point where it would theoretically balance) of the sculpture in order to mount in best (for least resistance).

If everything was just one material, I would just find the center points of all the rectangles, and then just average them, but as picture there is a steel frame and Plexiglas interior pieces. Where would this piece balance? How can I scrip this?

Thanks!! (ignore the thin lines in the image)

Attachments:

screenshot_Sat_Sep_19_18.33.19.png, 35 KB
screenshot_Sat_Sep_19_18.34.04.png, 28 KB

Replies to This Discussion

Permalink Reply by peter fotiadis on September 20, 2015 at 4:14am

Like this?

Note: Load R file first.

Note: Rhino Zoom extends for some reason displays nothing (maybe some point escaped to a parallel universe). Anyway this happens occasionally.

Attachments:

CoG.3dm, 1.1 MB
CoG.gh, 22 KB

Permalink Reply by Ol OneEye on September 20, 2015 at 11:46am

Hey thanks for your reply, and the work you have done! To be honest, I am still trying to figure out your definition, this technique is all very new to me. If you wouldnt mind, I have attached my definition, any Idea how to connect the two?? I put the outcome breps (plexisheet and metal frame) all the way to the right THANKS!

Attachments:

GS22 (Tj's Project).gh, 56 KB

Permalink Reply by peter fotiadis on September 20, 2015 at 12:32pm

OK ... but this (and I'm talking about the naive definition that I've provided in the first place) is NOT the way for doing that type of stuff ... but if I do it - via C# - by properly managing volatile data in order to assign density "on-the-fly" on "a-per-object" basis ... well ... you are not ready for that type of freaky things.

But is good to imagine:

Imagine a List (L) with your objects. Imagine a tree (DT) with densities (i.e. data properly classified per material class (meaning branches) and per material (meaning items)).

Then imagine a "capability" where you create a "combo" data tree (with 2 dimensions) with L.Count branches where subbranch 0 hosts the brep and 1 hosts the density (assigned on the fly: by choosing the desired density from DT).

Then ... blah, blah

Attachments:

GS22TjsProject_V1.gh, 60 KB

Permalink Reply by Ol OneEye on September 20, 2015 at 12:43pm

Haha! This is amazing! Thanks! I am going to spend the afternoon trying to figure out how you did this, I had know idea it was this complicated. So when you say not the way of doing this what do you mean? Is this definition not accurate? Somewhat accurate? It doesnt have to be precise.

Permalink Reply by Ol OneEye on September 20, 2015 at 1:22pm

So If i understand this correctly you are taking the Total mass of the sculpture (two different densities x their respected volumes) and dividing that by the centroid of the geometry x its respected mass?

So: Total Mass / average point of (mass x centroid of geometry)

I am mainly confused by the mass x centroid of geometry, what does that give you?

Permalink Reply by Ol OneEye on September 20, 2015 at 1:39pm

Sorry edit, so its not the average point of the (mass x centroid of geometry) but the mass addition of (mass x centroid of geometry).

SO: Total mass / mass addition of (mass x centroid of geometry

Permalink Reply by peter fotiadis on September 20, 2015 at 11:46pm

BTW: I'll post later (in the Name of Science) the correct way to do that ...forget calculations ... think the managerial aspect of the process:

1. You have 1 to 666 breps that randomly participate into a "combo". For whatever reason these may (or may not) be valid "solids" (closed polysurfaces, that is). Invalid ones should yield a log "report" (why, that is).

2. The valid ones may have this density or that density depending on your mood, aesthetics and most probably due to other trivial factors, he he, for instance the cost of a gold frame is "slightly" bigger than an iron one. Or the cost of a cheapo plexiglas item VS a glass made one. Or the cost/availability of compatible fasteners ... blah, blah.

3. Due to 2 you actually create a possible (out of N) scenario that MAY (or not) be the ideal/approved one.

4. For each alteration on 2 a new scenario is created (and stored).

5. For each alteration on 1 a new scenario is also created (and stored).

Permalink Reply by peter fotiadis on September 21, 2015 at 4:23am

OK, here's a tech preview (WITHOUT the WOW "scenario" stuff: I'm still thinking ways to demonstrate the whole approach (*) with the less(?) complicated(??) way).

(*) individually modify things in collections, that is.

Since the WOW stuff it would been addressed solely via code and since it's actually the 99% of the whole puzzle ... I've used solely code for the 1% as well (does this make any sense? not much I guess, he he).

Note: Load R file first.

Moral: roll the bones (since it's the only mode currently working (dice == true)).

best, Peter

Permalink Reply by peter fotiadis on September 21, 2015 at 4:28am

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